My cat is banned from entering the bedroom when we're sleeping here, since she keeps waking us up. However, actually implementing the ban is hard, because she learned how to open the doors. As a temporary measure, I'm tying together the handles (both of the doors have one inside), but I'm looking for a more permanent solution.
The solution doesn't need to actually lock the door, it's good as long as the cat (~4.5 kg) can't just use her body weight to open it. It's important however, for the solution to be able to be locked/unlocked from both inside and outside (for inside-only solutions, I found latches, so if there's nothing better, I'll probably settle for it), since me and my wife usually go to sleep at different times, so one person should be able to lock it inside, and the other should be able to then open the door from outside.